Screen



J. A. DAY.

SCREEN.

APPLICATION FILED 8.2111920.

Patented m0. 28,1920.

iqul

PATENT OFFECE.

UNITED STATES JAMES A. DAY, OF KNOXVILLE, TENNESSEE.

SCREEN.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed February 27, 1920. Serial No. 361,789.

more particularly to apparatus or machines 1 of the rotary beater type.

The invention has for its object to provide in a machine of the kindstated, a novel and improved discharge screen or grating through whichthe crushed or pulverized material passes, a. structure being providedwhich permits adjustment of the screen or gra ing according to thedesired size of the crushed particles.

The invention also has for its object to provide an adjustable screen orgrating which is so constructed and arranged that the adjustment can bemade from the outside of the machine, and without stopping the machine.

The objects stated are attained by means of a construction andarrangement of parts to be hereinafter described and claimed, and whilethe preferred embodiment of the in vention has been disclosed, it willbe understood that various changes and modifications may be made withouta departure from the spirit and scope of the invention as claimed.hereinafter.

In order that the invention may be better understood, referen e is hadto the accompanying drawing forming a part of this specification.

In the drawing,

Figure 1 is a plan view of the invention partly in section, and

Fig. 2 is a longitudinal section on the line 22 of Fig. 1.

Referring specifically to the-drawing, 5 denotes the side walls of thebottom or outlet portion of a pulverizer of the tyne disclosed in PatentNo. 1203314, dated October 31, 1916. This portion of the machinecontains a screen or grating through which the lime stone or othermaterial passes after being reduced to the proper size by the retarybeater members, the latter not being shown as they form no part of thepresent invention.

The discharge screen or grate is composed of a plurality of bars 6 whichare wider at one end than at the other. The shape of the bflISlSsubstantially triangular and they are arranged in alternately reverserelation. the apex of one triangle beingadjacent to the base of the nexttriangle. The bars extend transversely between the side walls 5 of themachine, and they are spaced suflicientl to permit the crushed materialto pass. Ihe spacing of the bars may be varied by movmg them in thedirection of their length,

one bar being moved in one direction, and i the next bar in the oppositedirection. By reason of the shape of the bars the opposite edges thereofare arranged at oblique angles to the line of movement of the bars, andsaid edges are parallel. It will therefore be seen that by moving thebars in the direction of their length, the width of the spaces therebetween may be varied, and any desired width may be obtained accordingto the desired degree of fineness of the crushed or pulverized material.

The bars 6 are slidably supported at their ends in curved slots 8 in theside Walls 5, and the screen or grating is thus made concave as usual.The smaller ends of the bars are continued-in the shape of guide stems9, the opposite side edges of which are parallel, said stems seating inthe slots. For a short distance from their wider ends, the opposite sideedges of the bars are parallel, and here the bars are spaced a distanceto allow the stem of one bar to seat between the two adjacent bars, theparallel edges being in sliding" contact and thus serving to guide thebars when they are moved lengthwise as hereinbefore described to varythe width of the spacing.

0n the outside of the walls 5 are outstanding ledges 10 which are flushat the top with the bottoms of the slots 8 to serve as supports for theprojecting ends of the bars 6. These ledges have upstanding marginalflanges 11 at their longitudinal edges. and also upstanding end flanges12, said flanges carrying a removable cover plate 13. The ledges and ther fiancee, and the cover plate form a housing for the proiecting ends ofthe bars 6, and also a cover for the slots 8 to prevent the escape ofdust through said slots. Any dust settling in the housing so as tointerfere with the adjustment of the bars 6. can be readily dis.- posedof upon removal of the cover plate1 3.

The longitudinal adjustment of the bars 6, to vary the spacingtherebetween, is made by screws 14; threaded into nuts 15 seatingnon-rotatably in recesses 16 in thewider ends of the bars. The screwsare rotatably;

supported by the flanges 11, and held against longitudinal travel bycollars ,17.

In line With the screw receiving aperture of the nuts 15, the bars 6have longitudinal bores 18 to seat the projecting portions of the screwstems 14. Various other means may be provided forshifting the bars 6either singly or simultaneously. The screW' charge slots, and positionedalongside' each other and spaced at their longitudinal edges, said edgesbeing arranged at an oblique angle tothe line of movement of the bars tovary the Width of the spaces When the bars are shifted longitudinally,and means for shifting the bars.

2. A screen of the type described, comprising a plurality oflongitudinally movable bars positioned alongside each other and spacedat their longitudinal edges, said edges being arranged at an'obliqueangle to the line of movement of the bars to vary the Width of thespaces when the bars are shifted longitudinally, said bars being insliding contact with; each other at their ends, and said contiguousendportions of l the bars being parallel to the path in which.

the bars are shiftable, and means for shifting alternate ones of thebars in opposite directions." p

In testimony Whereof'I afiix'niy signature- JAMES A; DAY.

